Page 618 - The ROV Manual - A User Guide for Remotely Operated Vehicles 2nd edition

618 CHAPTER 22 It’s the Little Things That Matter
(Continued)
Vehicle Size
Task SML
b. Longitudinal search from stern X D D
c. Lateral search P P P
Section searches (quarter/halve vessel) versus landmark/high-exposure searches
Note: All hull inspections are greatly enhanced with possession of a diagram of the hull to be inspected displaying prominent features on the hull. With a full diagram of the hull, feature-based visual searches will ensure coverage of that section of the hull inspection.
a. Obtain “as built” drawings and perform landmark/high-exposure searches
b. Full coverage search
c. Convenience of breaking vessel down into sections versus full ship
Adrift and tied to vessel hull search
P P P NA NA NA NA NA NA
Note: During tidal flows, it may be beneficial to place the submersible in the water and then scan as the submersible drifts by. This allows the submersible to drift (and look) downstream facing down-current or attempt up-current vehicle swim while tied off to the stern of the vessel to be inspected. Caution should be exercised when doing drift-by scans due to the possibility of the submersible snagging on items in the water column or attached to the vessel to be inspected.
a. Drift in current from bow to stern while conducting hull scan
b. Tie off to bow and do drift scan with sub facing down-current
c. Tie off to stern in current and do up-current search
P P P D D D X D P
Pier/Mooring/Anchor/Hull Search from Both Shore and Vessel
Shore to structure/vessel
Note: The least resource-intensive hull search scenario is with the ROV deployed from shore while conducting a hull or structure inspection. This will form a high incidence of hull inspection scenarios. In areas of low tidal flow, this is a simple and efficient method of hull and structure inspection.
a. Run bilge keel or keel
b. Inspect running gear to stuffing block
c. Inspect sea chest(s)
d. Inspect thrusters
e. Inspect through-hull fittings
f. Inspect bulkhead/pilings
g. Run anchor chain
h. Acoustically/visually search bottom under vessel
Vessel to same vessel
X D P P P P P P P P P P P P P P P P NA NA NA P P P
Note: Inspections of hulls while positioned aboard the same vessel are convenient. It may, however, be difficult to inspect the underside of the vessel.
a. Run bilge keel or keel
b. Inspect running gear to stuffing block
c. Inspect sea chest(s)
X D P P P P P P P
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